Function unit for dual wiring system

ABSTRACT

A function unit having easy exchangeability in a dual wiring system is provided. The function unit is detachably connected to a gate device mounted in a wall surface of a structure, and connected to both of an electric power line and an information line previously installed in the structure. The function unit has at least one of functions for supplying electric power from the electric power line, outputting information from the information line and inputting information into the information line when connected with the gate device. The function unit has a module connector, which is configured to simultaneously establish both of supplying the electric power from the gate device to the function unit, and making a signal transmission between the gate device unit and the function unit when connected to a module port formed at the gate device. To improve function expandability, an additional function unit may be detachably connected to the function unit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to four applications: “BASE UNIT FOR DUALWIRING SYSTEM” filed even date herewith in the names of MasahiroYAMAMOTO et al. as a national phase entry of PCT/JP2005/024200 filedDec. 22, 2005; “DUAL WIRING SYSTEM” filed even date herewith in the nameof Masahiro YAMAMOTO et al. as a national phase entry ofPCT/JP2005/024194 filed Dec. 22, 2005; “DUAL WIRING SYSTEM” filed evendate herewith in the name of Tsunehiro KITAMURA et al. as a nationalphase entry of PCT/JP2005/023873 filed Dec. 27, 2005; and “FUNCTION UNITFOR DUAL WIRING SYSTEM” filed even date herewith in the name of MasahiroYAMAMOTO et al. as a national phase entry of PCT/JP2005/024199 filedDec. 22, 2005; all of which claim Japan application Nos. 2005-200990,2005-200991, 2005-200992, 2005-200993, and 2005-200994 all filed Jul. 8,2005, which applications are assigned to the assignee of the presentapplication and all four incorporated by reference herein.

TECHNICAL FIELD

The present invention relates to a dual wiring system, which can be usedfor the supply of electric power and the input and output of informationthrough an electric power line and a signal line installed in astructure.

BACKGROUND ART

Due to popularization of the Internet, it has been demanded to ensurethe accessibility to information networks at many locations in buildingstructures such as general houses and office buildings. For example,Japanese Patent Early Publication [kokai] No. 11-187154 discloses amultimedia wiring system having a distribution board for controlling anelectric power line and various kinds of signal lines installed in astructure in a centralized control manner, and a multimedia receptaclepanel, which is adapted in use to be mounted in an indoor wall surface,and connected to the distribution panel through the electric power lineand the signal lines. For example, the multimedia receptacle panel has apower receptacle for supplying commercial electric power to an electricappliance, receptacle for receiving broadcasting programs such as groundwave broadcasting, satellite broadcasting, and cable television, modularjacks for analog and digital lines used for the Internet and telephonecommunication. By use of this multimedia wiring system, the convenienceof multimedia products is enhanced to obtain comfortable living andworking environments in the information society.

By the way, the above-described multimedia receptacle panel is usuallymounted in the wall surface, and connected to the electric power lineand the signal lines under construction works of the buildingstructures. This means that the functions of the multimedia receptaclepanel are determined at the time of the construction works. Therefore,after the construction works are finished, it is difficult to add a newfunction to the multimedia receptacle panel or exchange a part of thefunctions of the existing multimedia receptacle panel for anotherfunction. In addition, when exchanging the existing multimediareceptacle panel for another multimedia panel, a repair work is needed.However, such a repair work is not easy for general users to perform,and the costs of the repair work become a burden to the user.

Thus, the conventional multimedia receptacle panel still has plenty ofroom for improvement from the viewpoints of easy exchangeability andfunction expandability.

SUMMARY OF THE INVENTION

Therefore, a primary concern of the present invention is to provide afunction unit with improved function expandability and easyexchangeability in a dual wiring system.

That is, the function unit for dual wiring system of the presentinvention is adapted in use to be detachably connected to a gate devicemounted in a wall surface of a structure, and connected to both of anelectric power line and an information line installed in the structure.The function unit is configured to provide at least one of functions forsupplying an electric power from the electric power line, outputtinginformation from the information line, and inputting information intothe information line when connected with the gate device. The functionunit is characterized by having one of a module connector and a moduleport, which is configured to simultaneously establish both of supplyingthe electric power from the gate device to the function unit, and makinga signal transmission between the gate device unit and the function unitwhen connected to the other one of the module connector and the moduleport formed at the gate device.

According to the present invention, since both of the supply of electricpower from the gate device to the function unit and the mutualcommunication of the information signal between the gate device and thefunction unit can be simultaneously obtained by the connection betweenthe module connector and the module port, a general user can easilyexchange the function unit already connected to the gate device foranother function unit without performing a laborious repair work. Inaddition, when a plurality of gate devices are mounted in wall surfacesat plural locations in the structure, each of the gate devices aresharable among a plurality of function units having various kinds offunctions such as receptacle, switch, sensor, controller, monitor andspeaker. Therefore, an increased degree of freedom of layout of thefunction units provides comfortable and convenient living and workingenvironments to meet the user's needs.

In the present invention, it is preferred that the function unit has atleast one of a power supply unit configured to supply the electric powerprovided by the connection between the module connector and the moduleport to an electric appliance by means of electromagnetic coupling, anda transceiver unit configured to convert an information signal providedby the connection between the module connector and the module port intoan optical signal and output the optical signal, and convert an opticalsignal provided from outside to an information signal and transmit theinformation signal to the information line through the gate device. Inthis case, since the electric power transmission and/or the signaltransmission are performed in a noncontact manner by means of theelectromagnetic and optical couplings, it is possible to minimizetransmission loss of the electric power and/or the electric signal, andoperate the function unit with reliability.

In addition, it is preferred that the function unit has one of anelectric power port and an electric power connector, which is detachablyconnected to the other one of the electric power port and the electricpower connector formed at an additional function unit to supply theelectric power from the function unit to the additional function unit,and one of an information signal port and an information signalconnector, which is detachably connected to the other one of theinformation signal port and the information signal connector formed atthe additional function unit to make a signal transmission between thefunction unit and the additional function unit. In particular, it ispreferred that the electric power port and the electric power connectorare configured to supply the electric power from the function unit tothe additional function unit by means of electromagnetic coupling, andthe information signal port and the information signal connector areconfigured to make the signal transmission between the function unit andthe additional function unit by means of optical coupling. Theavailability of the additional function unit further increases thefunction expandability in the dual wiring system.

Moreover, it is preferred that the function unit has a joining meansconfigured to mechanically connect the additional function unit to thefunction unit. For example, the joining means is formed with an engagingportion such as elongated projection and groove formed on the functionunit, and a joining member configured to slidably contact the engagingportion. A region of the joining member can be engaged to the engagingportion of the function unit, and the remaining region of the joiningmember is engaged to an engaging portion formed on the additionalfunction unit, so that the mechanical connection between the functionunit and the additional function unit is achieved. In this case, it ispossible to improve the reliability of the supply of electric power andthe mutual communication of the information signal between the functionunit and the additional function unit, and prevent an accidental fallingof the additional function unit from the function unit.

These and additional features of the present invention and advantagesbrought thereby will become more apparent from the following preferredembodiments, referring to the attached drawings.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a dual wiring system according to apreferred embodiment of the present invention;

FIG. 2 is a schematic circuit diagram of a gate device and a functionunit for the dual wiring system;

FIG. 3A is an exploded perspective view of the function unit, and FIG.3B is a plan view of a module port of the gate device;

FIG. 4 is a perspective view of the function unit (viewed from the rearside);

FIG. 5 is a schematic circuit diagram of another function unit;

FIG. 6 is a schematic circuit diagram showing the internal structure ofan additional function unit for the dual wiring system;

FIGS. 7A and 7B are front and rear perspective views of the additionalfunction unit connected to the function unit;

FIG. 8 is a perspective view of the additional function units connectedto the function unit;

FIG. 9 is a plan view of an attachment plate for fixing the gate deviceto a switch box;

FIG. 10A is an exploded perspective view illustrating how to connect theadditional function unit to the function unit, and FIG. 10B is aperspective view of a joining member;

FIGS. 11A and 11B are front and side views of the additional functionunit according to a first modification of the embodiment, and FIG. 11Cis a perspective view illustrating how to use the joining member;

FIGS. 12A and 12B are front views of another additional function units;

FIGS. 13A and 13B are perspective views illustrating how to make aconnection between the additional function units according to a secondmodification of the embodiment; and

FIGS. 14A to 14C are front and side views of the additional functionunit according to a third modification of the embodiment.

DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

A function unit for dual wiring system of the present invention isexplained in detail according to the following preferred embodiments.

As shown in FIG. 1, the dual wiring system of this embodiment has apower supply line L1 and an information line L2 installed in a buildingstructure, which are connected to commercial power source AC and theinternet network NT through a distribution board 1, switch boxes 2embedded in wall surfaces at many locations in the building structure,gate devices 3 mounted in the switch boxes and connected to the powersupply line L1 and the information line L2, and a plurality of functionunits 4 each having the capability of providing at least one offunctions for supplying electric power from the power supply line L1,outputting information from the information line L2 and inputtinginformation into the information line L2 when connected with one of thegate devices 3. In the present specification, the wall is not limited tothe sidewall formed between adjacent rooms. That is, the wall includesexterior wall and interior wall of the building structure, and theinterior wall includes the sidewall, ceiling and floor. In FIG. 1, “MB”designates a main breaker, “BB” designates a branched breaker, and “GW”designates a gateway (e.g., router or built-in hub).

As shown in FIG. 2, each of the gate devices 3 has terminals (30 a, 32a) connected to the power supply line L1 and the information line L2,and bus-wiring terminals (30 b, 32 b) at its rear surface, and a moduleport 34 at its front surface, which is composed of an electric powerport 34 a for supplying the electric power and an information signalport 34 b for accessing the information line. For example, as shown inFIG. 3B, each of the electric power port 34 a and the information signalport 34 b is configured in a substantially rectangular shape such thatthey are arranged in parallel to each other. As described later, themodule port 34 is detachably connected to a module connector 42 of thefunction unit 4. The module port 34 may be formed at a side of the gatedevice 3 such that the function unit 4 is detachably connected to thegate device 3 in a direction along the wall surface (i.e., insubstantially parallel with the wall surface).

With respect to the gate devices 3, a distance between the electricpower port 34 a and the information signal port 34 b, terminalarrangements in each of the electric power port 34 a and the informationsignal port 34 b, and the shape of the module port 34 are standardized(stylized) to make each of the gate devices 3 shareable among thefunction units 4. In other words, since the module ports 34 of the gatedevices 3 are formed to be equal to each other, the function unit 4having the module connector 42 connectable with the module port 34 canbe commonly used for all of the gate devices 3 in the dual wiringsystem. Thus, the function unit 4 connected to one of the gate devices 3can be exchanged with another function unit 4 by a simple operation ofconnecting and disconnecting between the module port 34 and moduleconnector 42 without performing a repair work. Therefore, the dualwiring system of the present invention is excellent in easyexchangeability of the function unit 4.

The function unit 4 of this embodiment has circuit components shown inFIG. 2 therein, and the module connector 42 in its rear surface, asshown in FIG. 3A. The module connector 42 is composed of an electricpower connector 42 a and an information signal connector 42 b. Forexample, as shown in FIG. 4, each of the electric power connector 42 aand the information signal connector 42 b is configured in asubstantially rectangular shape such that they are arranged in parallelto each other. By connecting the module connector 42 of the functionunit 4 to the module port 34 of the gate device 3, the electric powerconnector 42 a and the information signal connector 42 b can besimultaneously connected to the electric power port 34 a and theinformation signal port 34 b.

In this embodiment, the module port 34 also has a guide portion 35 suchas a ring-like wall or a ring-like groove extending around the electricpower port 34 a and the information signal port 34 b. This guide portion35 is formed to be engageable to an engaging portion 45 such as aring-like wall of the module connector 42, which is formed on the rearsurface of the function unit 4. Since the electric power connector 42 aand the information signal connector 42 b are simultaneously connectedto the electric power port 34 a and the information signal port 34 b bysimply engaging the engaging portion 45 to the guide portion, it ispossible to improve the removability of the function unit 4. The moduleport 34 and the module connector 42 may be formed by female and maleconnectors.

The electric power provided to the function unit 4 through the gatedevice 3 and the mutual communication of the information signal betweenthe function unit 4 and the information line L2 are used for variouspurposes according to the kind of the function unit 4. For example, whenthe function unit 4 is connected to the gate device 3 mounted in thewall surface at a high position near the ceiling, it preferably has areceptacle function of receiving a plug with hook of a lightingapparatus, security function such as a motion sensor, temperaturesensor, and monitoring camera, or a sound function such as speaker. Inaddition, when the function unit 4 is connected to the gate device 3mounted in the wall surface at a middle height, at which the functionunit 4 can be easily operated by the user, it preferably has a switchfunction of turning on/off the lighting apparatus, control function forelectric appliances such as air-conditioning equipments, or displayfunction such as liquid crystal display. In addition, when the functionunit 4 is connected to the gate device 3 mounted in the wall surface ata low position near the floor, it preferably has a receptacle functionfor receiving a plug of an electric appliance such as electric vacuumcleaner, the sound function such as speaker, or a footlight function.

Next, an internal structure of the function unit 4 of this embodiment isexplained. As shown in FIG. 2, the function unit 4 is provided with anAC/AC converter 60, DC power section 61, transceiver section 62, E/Oconverter 63, O/E converter 65, and a function section 67. The AC/Acconverter 60 converts commercial AC voltage to a lower AC voltage havingan increased frequency, and applies the lower AC voltage to a coil 72wound around a core 70. The DC power section 61 generates an operatingvoltage of the internal circuit components from a stable DC voltageobtained by rectifying and smoothing the lower AC voltage. Thetransceiver section 62 transmits and receives the information signal forenabling the mutual communication through the information line L2. TheE/O converter 63 converts the information signal received from theinformation line L2 to an optical signal, and outputs the optical signalthough a light emitting device (LED) 64. On the other hand, the O/Econverter 65 receives the optical signal provided from the outside,e.g., an additional function unit 5 described later by a light receivingdevice (PD) 66, and converting the received optical signal into theinformation signal to transmit it to the transceiver section 62. Thefunction section 67 provides the above-described function of thefunction unit 4. In the case of FIG. 2, the function section 67 isformed by power receptacles.

In the case of the function unit 4 having another function section 67such as sensor or controller, a processing section 68 and I/O interface69 are formed between the transceiver section 62 and the functionsection 67, as shown in FIG. 5. The processing section 68 has functionsof performing a signal processing of the information signal received bythe transceiver section 62 to transmit the processed signal to thefunction section 67 through the I/O interface 69, and receiving the datasignal provided from the function section 67 to output as theinformation signal. Electric power needed to energize the transceiversection 62, processing section 68 and the function section 67 issupplied from the DC power section 61. When an AC/DC converter forconverting the commercial AC voltage into a required DC voltage is usedin place of the AC/AC converter 60, the DC power section 61 can beomitted.

When the function section 67 is formed by a switch, operation dataobtained by operating the switch is transmitted to the processingsection 68 through the I/O interface 69. Then the processed data is sentto, for example, an infrared remote controller (not shown) through thetransceiver section 62, so that an electric appliance to be controlledis turned on/off by receiving a remote control signal emitted from theinfrared remote controller. In addition, when the function section 67 isformed by a sensor, data detected by the sensor is transmitted as theinformation signal to the information line L2, and then informed to theuser by a required communicator. When the function section 67 is formedby a speaker, sound data provided as the information signal through theinformation line L2 is output from the speaker. When the functionsection 67 is formed by a monitoring camera, compression encoding ofimage data taken by the monitoring camera is performed, and then outputas the information signal. Furthermore, when the function section 67 isformed by a monitor, image data provided through the information line L2is decoded, and then displayed on the monitor. When the function section67 is simply formed by the power receptacle, as described above, theprocessing section 68 and the I/O interface 69 can be omitted. Thus,since the function units 4 having various kinds of the function sections67 can be detachably used in the dual wiring system, the degree offreedom of layout of the function units 4 can be remarkably improved.

The coil 72 wound around the core 70 in the function unit 4 is used as apower supply means for supplying electric power from the function unit 4to the additional function unit 5 in a noncontact manner. That is, thecoil 72 wound around the core 70 of the function unit provides anelectromagnetic coupling portion that works as a first side of atransformer. On the other hand, as shown in FIG. 6, the additionalfunction unit 5 has an electromagnetic coupling portion comprised of acoil 82 wound around a core 80, which works as a second side of thetransformer. Therefore, by forming electromagnetic coupling between thefunction unit 4 and the additional function unit 5, a low AC voltage isinduced in the coil 82 of the additional function unit 5 to achieve thesupply of electric power from the function unit 4 to the additionalfunction unit 5. In this embodiment, since the low. AC voltage havingthe higher frequency than the commercial AC voltage is obtained by theAC/AC converter 60, the electromagnetic coupling portions used as thetransformer can be downsized.

In addition, the light emitting device (LED) 64 of the E/O converter 63of the function unit 4 is used to transmit the optical signal as theinformation signal to the additional function unit 5 in a noncontactmanner. In this case, as shown in FIG. 6, a light receiving device (PD)86 is disposed in the additional function unit 5 such that the lightemitting device 64 of the function unit 4 is in a face-to-face relationwith the light receiving device 86 of the additional function unit 5when the additional function unit 5 is connected to the function unit 4.Similarly, to transmit the optical signal as the information signal fromthe additional function unit 5 to the function unit 4, the additionalfunction unit 5 has a light emitting device (LED) 84, which is disposedto be in the face-to-face relation with the light receiving element (PD)66 of the function unit 4 when the additional function unit 5 isconnected to the function unit 4. Thus, each of the function unit 4 andthe additional function unit 5 has the pair of the E/O converter (63,83) and the O/E converter (65, 85) as an optical coupling portion toenable the mutual communication of the information signal therebetween.

As shown in FIGS. 3A and 4, it is preferred that the electromagneticcoupling portion X used for the supply of electric power and the opticalcoupling portion Y used for the mutual communication of the informationsignal are disposed at a side surface of the function unit 4 to bespaced from each other by a required distance. In addition, the pair ofthe electromagnetic coupling portion X and the optical coupling portionY are formed at each of both sides of the additional function unit 5, asshown in FIG. 6. That is, the optical coupling portion Y1 formed at oneside (e.g., left side) of the additional function unit 5 is composed ofthe light receiving device 86 located at the upper side and the lightemitting device 84 located at the lower side, and the optical couplingportion Y2 formed at the opposite side (e.g., right side) of theadditional function unit 5 is composed of a light emitting device 94located at the upper side and a light receiving device 96 located at thelower side. In this case, even when a plurality of additional functionunits 5 are connected in series to the function unit 4, it is possibleto ensure the mutual communication of the information signal between theadditional function units 5 as well as between the function unit 4 andthe additional function unit 5. It is also preferred that a lighttransparent cover is attached to the respective optical coupling portion(Y, Y1, Y2) to protect the optical devices. As shown in FIG. 6, theadditional function unit 5 further has circuit components for achievingthe power supply and the mutual communication of the information signalbetween adjacent additional function units 5. However, since they aresubstantially the same as the circuit components used in the functionunit 4, duplicate explanations of the same circuit components areomitted.

As shown in FIG. 3A, when the function section 67 (e.g., powerreceptacle) is formed at the front surface (i.e., the opposite surfaceto the rear surface having the module connector 42) of the function unit4, and the pair of the electromagnetic coupling portion X and theoptical coupling portion Y is formed at the side surface of the functionunit 4, the additional function units 5 can be connected to the functionunit 4 along the wall surface (i.e., in parallel with the wall surface).Therefore, it is possible to improve function expandability in the dualwiring system without spoiling the beauty in the interior spaces. Inaddition, the gate device 3 may be fixed to the switch box 2 such that apart of the gate device 3 is projected form the wall surface. In thiscase, the module port 34 is preferably formed at a side of the projectedportion of the gate device 3, so that the function unit 4 and theadditional function units 5 can be arranged along the wall surface.

Examples of the additional function unit(s) connected to the functionunit are introduced below. In FIGS. 7A and 7B, the function unit 4 has aspecial receptacle for a plug with hook of a lighting apparatus as thefunction section 67. The additional function unit connected to thefunction unit has a function of emitting an infrared remote signal. Inthis case, operation data obtained when another function unit having acontroller as the function section is operated by a user is transmittedto the additional functional unit 5 of FIG. 7A through the informationline L2, so that the infrared remote signal is emitted toward aninfrared signal receiving portion of an electric appliance such asair-conditioning equipment. In FIG. 7A, the numeral 58 designates aprotection cover detachably attached to the side of the additionalfunction unit 5 to protect the electromagnetic coupling portion X andthe optical coupling portion Y when not used. In addition, when thefunction unit 4 has the power receptacle, a relay or a semiconductorswitch may be connected to a circuit for the power receptacle such thatthe function of the power receptacle can be cancelled when the relay orthe semiconductor switch is operated according to a control signaltransmitted from another function unit.

In FIG. 8, first to third additional function units (5A, 5B, 5C) areconnected to the function unit 4. In this case, the function unit 4 hasgeneral power receptacles as the function section 67. The firstadditional function unit 5A detachably connected to the function unit 4has switches for turning on/off an air-conditioning equipment as thefunction section. The second additional function unit 5B detachablyconnected to the first additional function unit 5A has a controller ofthe air-conditioning equipment as the function section. In addition, thethird additional function unit 5C detachably connected to the secondadditional function unit 5B has a main unit of an intercom system as thefunction section.

The first additional unit 5A is provided with an operation button B1,stop button B2, and a CPU section for preparing the data according tothe operation of these buttons and transmitting the prepared data to theprocessing section through the I/O interface. This additional functionunit is preferably used to operate a lighting apparatus. The secondadditional function unit 5B is provided with a temperature setting dial51 for the air-conditioning equipment, LCD (liquid crystal display)monitor 52 for displaying the setting temperature, timer switch 53 foroperating the air-conditioning equipment for a desired time period, anda CPU section for preparing operation data according to the operation ofthe temperature setting dial 51 and the operation of the timer switch53, transmitting the operation data to the processing section throughthe I/O interface, and preparing the data to be displayed on the LCDmonitor 52.

The third additional function unit 5C is provided with a volume controlbutton B3, speaker 54, mode switch 55 for switching between thetransmitter function and the receiver function of the speaker 54, LCDscreen 56 for displaying the image taken by a TV camera placed at theentrance, release button B4 for releasing the door lock, and a CPUsection having a sound processing function for the speaker 54, imageprocessing function for the LCD screen 56, and the functions ofpreparing operation data according to the operations of the releasebutton B4 and the mode switch 55, and transmitting the preparedoperation data to the processing section through the I/O interface. Thefunction sections of the additional function units 5 are not limited tothe above examples. For example, a battery charger for electric shaver,electric toothbrush, mobile phone and portable audio player may beformed as the function section. In addition, the additional functionunit 5 having a handset function of the intercom system may be connectedto the function unit 4 mounted in an exterior wall surface at theentrance.

In the above explanation, the gate device 3 is directly fixed to theswitch box 2. If necessary, the gate device 3 may be fixed to the switchbox 2 through an attachment plate 75, for example, as shown in FIG. 9.In this case, after hooks formed at both sides of the attachment plate75 are engaged to the gate device 3, the attachment plate 75 with thegate device 3 is fixed to the switch box 2 by use of mounting screws.Alternatively, the gate device 3 may be directly fixed in the wallsurface by use of exclusive clamps without using the switch box 2. Onthe other hand, the function unit 4 can be attached to the wall surfaceby connecting the module connector 42 to the module port 34 of the gatedevice 3 in the switch box 2, then fixing a housing 10 of the functionunit 4 to the switch box 2 by use of mounting screw, and finally fittinga receptacle cover 11 and a cosmetic cover 12 to the front surface ofthe housing 10. Thus, a general user can easily finish the exchangingoperation of the function unit 4 without performing a repair work.

The additional function unit 5 can be attached to the function unit 4,as shown in FIG. 10A. That is, the cosmetic cover 12 is firstly removedfrom the function unit 4. In this embodiment, since the receptacle cover11 is separately formed from the cosmetic cover 12, the function section67 such as the power receptacle can be protected from an accidentalbreakage by the receptacle cover 11 during the connecting anddisconnecting operation for the additional function unit 5. After theadditional function unit 5 is arranged on the side surface of thefunction unit 4 such that the electromagnetic coupling portion X and theoptical coupling portion Y of the additional function unit 5 are in theface-to-face relation with them of the function unit 4, the additionalfunction unit 5 is mechanically coupled to the function unit 4 by use ofa joining member 90. The housing (10, 20) of each of the function unit 4and additional function unit 5 has horizontal guide rails (14, 24) atits upper and lower end portions. The numeral 15 designates a stopperwall formed at a substantially center position in the longitudinaldirection of the guide rail 14. On the other hand, as shown in FIG. 10B,the joining member 90 has a groove 92, in which the guide rails (14, 24)can be fitted.

As shown in FIG. 10A, on the condition that the guide rail 14 is fittedin the groove 92, a slide movement of the joining member 90 is performeduntil the joining member 90 contacts the stopper wall 15. As a result,the joining member 90 is engaged to the function unit 4 over about halflength of the joining member. On the other hand, the joining member 90is also engaged to the additional function unit 5 in a similar manner tothe above over the remaining length of the joining member. Thus, afterthe engagements between the joining member 90 and the function unit 4and between the joining member 90 and the additional function unit 5 arefinished at both of the upper and lower end portions, cosmetic covers(12, 22) are attached to the front surfaces of the function unit and theadditional function unit. Since the joining member 90 is held betweenthe cosmetic covers (12, 22) and the housings (10, 20) of the functionunit 4 and the additional function unit 5, it is possible to preventaccidental falling of the joining member 90, and obtain the stablemechanical connection therebetween without spoiling the beauty of them.

The followings are modifications of means for obtaining the stablemechanical connection between the function unit 4 and the additionalfunction unit 5 or between the additional function units 5.

As shown in FIGS. 11A to 11C, the additional function unit 5 accordingto a first modification of this embodiment has a pair of male and femaleconnectors (25, 27) at its both sides, each of which is comprised of theelectromagnetic coupling portion X and the optical coupling portion Y.For example, the male connector 25 is detachably connected to a femaleconnector formed at the function unit 4, and the female connector 27 isdetachably connected to a male connector formed on another additionalfunction unit 5. In addition, this additional function unit 5 has ahorizontal groove 26, in which a joining member 90A having in a similarcross section to the groove 26 can be fitted. As in the case of thejoining member 90 of FIG. 10B, one end of the joining member 90A isinserted into the groove 26 of the additional function unit 5 over abouthalf length of the joining member, and also the other end of the joiningmember 90A is inserted into a groove formed at an adjacent function unit4 or another additional function unit 5 over the remaining half lengthof the joining member to provide the stable mechanical connectiontherebetween.

In this modification, since the groove 26 has a substantiallytrapezoidal section configured such that an opening formed at the rearsurface of the additional function unit 5 corresponds to a narrow sideof the trapezoidal section, the falling of the joining member 90A fromthe groove 26 can be prevented without using the cosmetic cover. Inaddition, the user can be accessed to the joining member 90A through theopening of the rear surface of the additional function unit 5, it ispossible to easily perform the slide movement of the joining member 90Ain the groove 26. The shape of the groove is not limited to thetrapezoidal section on the condition that the joining member 90A can notremoved from the opening formed at the rear surface of the additionalfunction unit 5.

As shown in FIG. 12A, only the electromagnetic coupling portion X may beformed by the female and male connectors. To ensure the functionexpandability of the additional function unit 5, when the male connectoris provided at one side of the additional function unit, the femaleconnector is provided at the other side thereof. Alternatively, as shownin FIG. 12B, each of the electromagnetic coupling portion X and theoptical coupling portion Y may be formed by female and male connectorsconfigured in arcuate recess and projection. Thus, when the use of thefemale and male connectors provides accurate positioning between theadjacent additional function units, and consequently the reliability ofthe supply of electric power and the input and output of the informationsignal is improved.

As a second modification of this embodiment, it is preferred that eachof the upper and lower end portions of the additional function units 5has a tapered end 21 with an engaging groove 23, and a joining member90B is configured to slidably contact the tapered end 21 and have a hook93 at its one end, which can be fitted in the engaging groove 23, asshown in FIG. 13A. In this case, after the joining member 90B is fittedto the tapered end 21 at each of the upper and lower ends of theadditional function unit, the joining member 90B is slid toward anadjacent additional function unit, as shown by the arrows in FIG. 13A.As a result, the stable mechanical connection between the adjacentadditional function units 5 can be obtained by use of this joiningmember 90B, as shown in FIG. 13B.

As a third modification of this embodiment, it is preferred that each ofthe upper and lower end portions of the additional function unit 5 has aconcave portion 28 for accommodating a joining member 90C, and a covermember 16 pivotally supported at its one end to the housing 20 of theadditional function unit 5, as shown in FIGS. 14A to 14C. The joiningmember 90C has a groove 92C, in which a guide rail 24C formed in theconcave portion 28 can be slidably fitted. In this case, after the covermember 16 is opened to access the joining member 90C, the joining memberis slid along the guide rail 24C, as in the case of FIG. 10A. Finally,the cover is closed to obtain the stable mechanical connection betweenthe adjacent additional function units 5. In addition, since the joiningmember 90C is always accommodated in the concave portion 28, there is noworry about loss of the joining member.

As an information-signal transmitting method available in the dualwiring system of the present invention, one of baseband transmission andbroadband transmission can be used. In addition, the protocol is notlimited to a specific one. For example, sound and visual informationsignals may be transmitted and received according to JT-H232 packet tomake the mutual communication between the base unit and the handset ofthe intercom system. In a control system, it is also preferred to use arouting protocol for a broadcast or a unicast that controlling can beperformed at a control ratio of 1:1 or 1:N according to operation data.Alternatively, it is preferred that the protocol used between the gatedevices is different from the protocol used in the function unitconnected to the gate device, and a protocol conversion is performed atthe gate device.

As shown in FIG. 1, since the function units 4 having the various kindsof functions have the common module connector 42 detachably connectableto each of the gate devices 3, and both of the power supply from thegate device 3 to the function unit 4 and the mutual communication of theinformation signal between the gate device 3 and the function unit 4 canbe simultaneously obtained by the connection between the module port 34and the module connector 42, a general user can easily exchange thefunction unit 4 already connected to one of the gate devices 3 foranother one of the function units without performing a laborious repairwork. In addition, when at least one additional function unit 5 isconnected to the function unit 4 along the wall surface, the functionexpandability can be further improved without spoiling the beauty in theinterior spaces. Thus, the function unit for dual wiring system of thepresent invention is effective to provide comfortable and convenientliving and working environments to meet the user's needs in theinformation society.

The invention claimed is:
 1. A plurality of function units for dualwiring system, comprising a first function unit which is adapted in useto be detachably connected to a gate device mounted in a wall surface ofa structure, and a second function unit configured to be connected tosaid gate device via said first function unit, said gate device beingconnected to both of an electric power line and an information lineinstalled in said structure, wherein the first function unit has afunction section, one of a module connector and a module port, which isconfigured to simultaneously establish both of receiving the electricpower from said electric power line, and making a signal transmissionbetween said information line and the first function unit for at leastone of outputting an information from said information line andinputting an information to said information line when connected to theother one of said module connector and said module port formed in saidgate device, wherein the first function unit further comprises in itslateral face one of an electric power port and an electric powerconnector, which is detachably connected to the other one of saidelectric power port and said electric power connector formed in thesecond function unit to supply the electric power from the firstfunction unit to the second function unit, wherein the first functionunit further comprises in its lateral face one of an information signalport and an information signal connector which is spaced from one ofsaid electric power port and said electric power connector at apredetermined interval and detachably connected to the other one of saidinformation signal port and said information signal connector formed inthe second function unit to make a signal transmission between the firstfunction unit and the second function unit, wherein said second functionunit has a function section, and comprises in its lateral face the otherof said electric power port and said electric power connector, whereinsaid second function unit further comprises in its lateral face theother of said information signal port and an information signalconnector which is spaced from said other of said electric power portand said electric power connector at a predetermined interval, andwherein said first function unit and said second function unit areconnected with each other in a direction along said wall surface.
 2. Thefunction units as set forth in claim 1, wherein said electric power portand said electric power connector are configured to supply the electricpower from the first function unit to the second function unit by meansof electromagnetic coupling, and said information signal port and saidinformation signal connector are configured to make the signaltransmission between the first function unit and the second functionunit by means of optical coupling.
 3. The function units as set forth inclaim 1, wherein said first function unit further comprises atransceiver unit configured to convert the information signal providedby the connection between said module connector and said module portinto an optical signal and transmit the optical signal to an electricappliance, and convert an optical signal provided from outside into aninformation signal and transmit the information signal to saidinformation line through said gate device.
 4. The function units as setforth in claim 1, wherein said first function unit further comprises apower supply unit configured to supply the electric power provided bythe connection between said module connector and said module port to anelectric appliance by means of electromagnetic coupling.
 5. The functionunits as set forth in claim 1, wherein said first function unit furthercomprises a joining means configured to mechanically connect the secondfunction unit to the first function unit.
 6. The function units as setforth in claim 5, wherein said joining means comprises an engagingportion formed on the first function unit, and a joining memberconfigured to slidably contact said engaging portion and make themechanical connection between the first function unit and the secondfunction unit when a region of said joining member is engaged saidengaging portion of the first function unit and the remaining region ofsaid joining member is engaged to an engaging portion formed on thesecond function unit.